Glazed wall constructions comprising operable windows or vents are well known. Such a window or vent typically has a "wiper" type gasket secured along its periphery to provide a weather seal between the window or vent and the surrounding structure. A problem often arises with such gaskets, however, in that they create too much drag as the window or vent is opened or closed, thereby making the window or vent difficult to operate. This drag is a function of two different characteristics of the gasket. First, to provide an adequate weather seal, the gasket is typically comprised of a relatively soft material which will have a high coefficient of friction. Second, not only the lower edge but also a significant portion of the interior surface of the gasket will contact the adjoining structure, and the increased contact surface area increases friction. On the other hand, if a more rigid material is selected for the gasket, the lower edge of the gasket may well not conform to the surface of the window sill, frame, or other adjacent structure. Further, a more rigid material would be unlikely to accommodate even minor variances in the clearance between the window or vent and its surrounding structure.
Thus there is a need for a gasket for operable windows and doors which reduces the amount of drag created as the window or door is operated.
There is a further need for an improved gasket for operable windows and doors which minimizes the area of surface contact between the gasket and the adjacent structure.
There is still a further need for a gasket for operable windows and doors which is comprised of a material which provides a continuous seal between the window or door and its surrounding structure while providing a low coefficient of friction.